NestedLines

A simple library to facilitate parsing line numbers into a common structure and enable indenting/outdenting/moving of lines.

Installation

If available in Hex, the package can be installed by adding nested_lines to your list of dependencies in mix.exs:

def deps do
  [
    {:nested_lines, "~> 0.1.0"}
  ]
end

Usage

For a given list of strings, use NestedLines.new!/1 to parse the strings into a %NestedLines{} struct.

["1", "2", "2.1", "2.2", "3", "3.1", "3.1.1"]
|> NestedLines.new!()

# %NestedLines{lines: [[1], [1], [0, 1], [0, 1], [1], [0, 1], [0, 0, 1]]}

Use NestedLines.new/1 for return values of {:ok, %NestedLines{}} or {:error, :message}

["1", "2", "2.1"]
|> NestedLines.new()

# {:ok, %NestedLines{lines: [[1], [1], [0, 1]}}

["1.1", "1.2"]
|> NestedLines.new()

# {:error, :invalid_initial_line_nesting}

With a %NestedLines{} stuct, you can then output the line numbers using NestedLines.line_numbers/2

["1", "1.1", "1.2", "2", "2.1", "2.1.1", "3", "4"]
|> NestedLines.new!()
|> NestedLines.line_numbers()

# ["1", "1.1", "1.2", "2", "2.1", "2.1.1", "3", "4"]

💡 Use the optional second argument to start the lines at a different number.

Use NestedLines.indent!/2 and NestedLines.outdent!/2 to indent and outdent lines, provided they maintain a valid line structure. For example:

["1", "2", "3"]
|> NestedLines.new!()
|> NestedLines.indent!(2)
|> NestedLines.line_numbers()
# Here the line at position 2 CAN be indented, resulting in:
# ["1", "1.1", "2"]

["1", "1.1", "2"]
|> NestedLines.new!()
|> NestedLines.indent!(2)
# Here the line at position 2 CANNOT be indented further and will raise an ArgumentError

Lines that have children can also be indented/outdented and their child lines will also indent/outdent accordingly by one position.

["1", "1.1", "1.1.1", "2"]
|> NestedLines.new!()
|> NestedLines.outdent!(2)
|> NestedLines.line_numbers()
# ["1", "2", "2.1", "3"]

["1", "2", "2.1", "3"]
|> NestedLines.new!()
|> NestedLines.outdent!(2)
# ArgumentError

Use NestedLines.tree for a representation of the lines as a nested struct. For example:

["1", "1.1", "2"]
|> NestedLines.new!()
|> NestedLines.tree()
# [
#  %{line: "1", children: [%{line: "1.1", children: []}]},
#  %{line: "2", children: []}
# ]

Contributing

We welcome merge requests for fixing issues or expanding functionality.

Clone and compile with:

git clone https://github.com/MBXSystems/nested_lines.git
cd nested_lines
mix deps.get
mix compile

Verify that tests and linting pass with your changes.

mix test
mix lint

All code changes should be accompanied with unit tests.